with links from there to other objects within that faint but rich constellation including, I’ve just discovered, COROT-7b the erstwhile lowest mass / diamtere exoplanetary record holder and hot super-Mercury / super-Venus / Rock Giant.

Green comes from a very specific kind of material called a polycyclic aromatic hydrocarbons — long-chain carbon molecules which are essentially soot

This does not read quite right.

Are they hydrocarbons or are they carbon?

As I understand it, PAHs come in a variety of forms, of which the largest are so carbon-rich that they are rather like soot or graphite. But smaller PAHs are more like heavy oil – or, in some cases, colourless solids – than soot.